Ethanol tolerant endoglucanase from Aspergillus niger isolated from wine fermentation cellar

The endoglucanase from Aspergillus niger isolated from a wine fermentation cellar was ethanol tolerant. Optimum pH and temperature of the endoglucanase activity was 5.0 and 60 °C. The endoglcuanase activity in 8% ethanol solution was higher than that in ethanol-free solution. Melting point temperature of the endoglucanase in 8% ethanol solution was 1.9 °C higher (40.0 °C) than that in ethanol-free solution (37.1 °C). At 45-60 °C, Gbbs free energe, ΔG, in 8% ethanol solution was higher than that in ethanol-free solution. The α-helix content increased in 8% ethanol solution. The increasing of α-helix content led to higher activity and better thermostability in high concentration ethanol solution. The acidic, thermostable and ethanol tolerant endoglucanase was valuable for bioethanol production by simultaneous saccharification and fermentation process.